package com.xszx.service;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

/**
 * @description:
 * @author:瓦达西瓦
 * @date:2024/10/31
 */
@SuppressWarnings("rawtypes")
public class SensitiveFilterService {



//敏感词过滤器：利用DFA算法  进行敏感词过滤



        private Map sensitiveWordMap = null;


        // 最小匹配规则
        public static int minMatchTYpe = 1;
        // 最大匹配规则
        public static int maxMatchType = 2;
        // 单例
        private static SensitiveFilterService instance = null;
        // 构造函数，初始化敏感词库
        private SensitiveFilterService() {
            sensitiveWordMap = new SensitiveWordInit().initKeyWord();
        }


        // 获取单例
        public static SensitiveFilterService getInstance() {
            if (null == instance) {
                instance = new SensitiveFilterService();
            }
            return instance;
        }


// 获取文字中的敏感词

        public Set<String> getSensitiveWord(String txt, int matchType) {
            Set<String> sensitiveWordList = new HashSet<String>();


            for (int i = 0; i < txt.length(); i++) {

// 判断是否包含敏感字符
                int length = CheckSensitiveWord(txt, i, matchType);

// 存在,加入list中
                if (length > 0) {
                    sensitiveWordList.add(txt.substring(i, i + length));

// 减1的原因，是因为for会自增
                    i = i + length - 1;
                }
            }

            return sensitiveWordList;
        }
// 替换敏感字字符

        public String replaceSensitiveWord(String txt, int matchType,
                                           String replaceChar) {
            String resultTxt = txt;
// 获取所有的敏感词
            Set<String> set = getSensitiveWord(txt, matchType);
            Iterator<String> iterator = set.iterator();
            String word = null;
            String replaceString = null;
            while (iterator.hasNext()) {
                word = iterator.next();
                replaceString = getReplaceChars(replaceChar, word.length());
                resultTxt = resultTxt.replaceAll(word, replaceString);
            }
            return resultTxt;
        }

        /**
         * 返回 字符串含有的拦截词  逗号隔开
         *
         * @param txt
         * @return
         */
        public String returnSensitiveWord(String txt) {
            String resultTxt = txt;
            StringBuilder sensitiveWord = new StringBuilder("");
            // 获取所有的敏感词
            Set<String> set = getSensitiveWord(txt, 1);
            Iterator<String> iterator = set.iterator();
            String word = null;
            String replaceString = null;
            while (iterator.hasNext()) {
                String str = resultTxt;
                word = iterator.next();
                replaceString = getReplaceChars("*", word.length());
                resultTxt = resultTxt.replaceAll(word, replaceString);
                if (!resultTxt.equals(str)){
                    sensitiveWord.append(word);
                    sensitiveWord.append(",");
                }
            }
            return sensitiveWord.toString();
        }
        /**
         * 获取替换字符串

         *
         * @param replaceChar
         * @param length
         * @return
         */
        private String getReplaceChars(String replaceChar, int length) {
            String resultReplace = replaceChar;
            for (int i = 1; i < length; i++) {
                resultReplace += replaceChar;
            }

            return resultReplace;
        }

        /**
         * 判断文本中包含敏感词个数
         * @param
         */
        public static boolean checkContainCount(String txt) {
            SensitiveFilterService filter = SensitiveFilterService.getInstance();
            Set<java.lang.String> hou = filter.getSensitiveWord(txt, 1);
            return hou.size() > 0;
        }
        /**

         * 检查文字中是否包含敏感字符，检查规则如下：<br>
         * 如果存在，则返回敏感词字符的长度，不存在返回0
         *
         * @param txt
         * @param beginIndex
         * @param matchType
         * @return
         */
        public int CheckSensitiveWord(String txt, int beginIndex, int matchType) {

// 敏感词结束标识位：用于敏感词只有1位的情况
            boolean flag = false;

// 匹配标识数默认为0
            int matchFlag = 0;
            Map nowMap = sensitiveWordMap;
            for (int i = beginIndex; i < txt.length(); i++) {
                char word = txt.charAt(i);
// 获取指定key
                nowMap = (Map) nowMap.get(word);

// 存在，则判断是否为最后一个
                if (nowMap != null) {

// 找到相应key，匹配标识+1
                    matchFlag++;

// 如果为最后一个匹配规则,结束循环，返回匹配标识数
                    if ("1".equals(nowMap.get("isEnd"))) {

// 结束标志位为true
                        flag = true;

// 最小规则，直接返回,最大规则还需继续查找
                        if (SensitiveFilterService.minMatchTYpe == matchType) {
                            break;
                        }
                    }
                }


// 不存在，直接返回
                else {
                    break;
                }
            }


            if (matchFlag < 2 && !flag) { // 长度必须大于等于1，为词
                matchFlag = 0;
            }
            return matchFlag;
        }






    }


